This invention relates to a method and apparatus for inspection of the refractory lining of a high temperature chamber such as is commonly employed in coking chambers of a battery of coke ovens, pneumatic steel treatment vessels, reheat furnaces for metallic workpieces and the like. More particularly, the present invention is addressed to the inspection of such a refractory lining while at a highly heated state by transmitting video signals to a remote location produced by a television camera that is moved along such refractory lining while the camera is located within a thermally-protective environment formed by an enclosure.
A typical coking chamber in a coke oven battery of present-day designs is approximately 2 feet wide, 12 to 18 feet high and 40 to 60 feet long. In a coke oven battery, the coking chambers except those at each end of the battery have a coking chamber at each side thereof. When a given coking chamber is pushed, the adjacent coking chambers at each side thereof have coal charges that have been advanced approximately midway through the coking process. While inspection of the refractory lining of a coking chamber is extremely important, it must be carried out within a relatively short period of time to not only minimize production losses but also to avoid critical temperature imbalances particularly since there is an empty coke oven chamber having side walls which are an integral part of the heating flues employed to heat the adjacent coking chambers.
Presently, the inspection of a coking chamber takes place immediately after the coke has been pushed into a transfer car at the coke side by a ram supported at the machine side. An inspector then views the emptied oven chamber from either the coke side or the machine side. The time available to the inspector for viewing the refractory lining is usually very short because the inspector is exposed to intense thermal radiation from the oven. In this respect, a coking chamber is heated to relatively high temperatures and within the range of 1200.degree. F to 2100.degree. F. The inspector, therefore, quickly views the internal refractory surface of the oven chamber to observe any deterioration of the refractory surface. The condition of the refractory surface is usually described in writing after the inspection by its appearance to the individual inspector. Such an inspection procedure is critically dependent upon the experience of the inspector and his ability to describe in terms meaningful to others exactly what he, in fact, observed during the relatively short inspection period. Moreover, this inspection procedure is further complicated by optical refraction caused by hot gases within the coking chamber during the inspection viewing period. Thus, extremely important information for timely maintenance and pollutant-free operation of a coke oven battery is presently compiled in a very rudimentary manner. While the foregoing description has been addressed to the problems and difficulties associated with the inspection of a refractory surface of a coke oven chamber, the present invention is equally applicable to the inspection of the refractory lining of other chambers including but not limited to vessels for pneumatic steel refining, furnaces for reheating metallic workpieces and the like.